Transferring a GPX file to a Montana whist on the road requires either carrying a laptop or using the dreadful Explore app.
However, there is another way if you have an new style iPad Pro with a USB C connector there's an easy way, since the iPad recognises external mass storage devices.
1) Open the File app on the iPad, create a folder called GPX or some such and drop your GPX file into it - you can save it from an email, or from whatever app you created it in, or from a download like the TET website.
2) Connect the Montana to the iPad - I use an Apple USB C to USB B connector and the Garmin micro USB cable
3) The Montana appears in the File app as a mass storage device
4) Find your GPX file, long press and "copy"
5) Navigate to the Garmin>GPX folder on the Montana. Long press, "paste" and you'll see your GPX file
6) Disconnect the Montana, then Where To>Tracks, and your track will be there!
Since the iPad Pro has a much better file manager, you can also store tracks for example in Drop Box, or even an external USB drive or SD card so you can't lose them while on a trip
However, there is another way if you have an new style iPad Pro with a USB C connector there's an easy way, since the iPad recognises external mass storage devices.
1) Open the File app on the iPad, create a folder called GPX or some such and drop your GPX file into it - you can save it from an email, or from whatever app you created it in, or from a download like the TET website.
2) Connect the Montana to the iPad - I use an Apple USB C to USB B connector and the Garmin micro USB cable
3) The Montana appears in the File app as a mass storage device
4) Find your GPX file, long press and "copy"
5) Navigate to the Garmin>GPX folder on the Montana. Long press, "paste" and you'll see your GPX file
6) Disconnect the Montana, then Where To>Tracks, and your track will be there!
Since the iPad Pro has a much better file manager, you can also store tracks for example in Drop Box, or even an external USB drive or SD card so you can't lose them while on a trip